7.3 uric acid level is on high-ish side of the normal range but not all that bad. Besides, there are many people with much higher uric acid levels who never get gout. Go figure.
Also, 7.3 was the reading on the day the test was done, as you point out. Those levels can jump around during a day and month, and to get an average reading you should probably have tests done over several months.
I couldn't find information on purine content of whey, but a nutrition-selling website
http://www.bulknutrition.com/p4617_Econo_W
hey_Protein_Scifit.html,
claims their whey powder is purine-free,so probably all whey powders are either purine-free or have a low content.
According to
http://home.bluegrass.net/~jclark/alkaline
_foods.htm, whey protein powder is an "alkalizing protein," meaning it contributes a bit toward making the body more alkaline rather than more acidic. This would be a good thing because it would help dissolve whatever excess uric acid you have so that it can be excreted.
I would think more about other things I'm digesting rather than just whey powder. Acidic vs. alkaline should be an important consideration. For example, meats, especially red meats, are quite acidic. Most vegetables and fruit are alkaline. The acidic/alkaline table at
http://home.bluegrass.net/~jclark/alkaline
_foods.htm website is pretty detailed.
There is a discussion on just what you are asking about on a bodybuilding website:
http://www.schwarzenegger.ca/forum/about22
31.html. It deviates from the whey powder issue into general guidelines on dealing with gout, but it's got some good information.